Straw for the conservation of small quantities of substances, in particular biological liquids

ABSTRACT

A straw ( 1 ) for the conservation of small quantities of substances, in particular biological substances, said straw comprising a segment of tube ( 2 ) provided, inside one end, with a stopper ( 3 ) including gel powder, characterized in that said straw stopper includes a thermoplastics material core ( 4 ) sheathed with filaments constituting a sheath ( 5 ).  
     The straw of the invention absorbs only a very small amount of the liquid contained therein.

[0001] The present invention relates to a straw for the conservation ofsmall quantities of substances, in particular biological liquids.

[0002] This type of straw, which is known as a “French straw”, wasdisclosed for the first time in French patent No. 995 878.

[0003] Straws manufactured in accordance with the above patent and useduntil now have a three-part stopper consisting of two plugs of a fibroussubstance with a powder between them that on contact with a liquid isconverted into an impermeable gel or paste adhering to the wall of thetube to create a sealed stopper.

[0004] Straws with a three-part stopper developed and marketed by theapplicant are entirely satisfactory. Nevertheless, some absorption ofthe liquid contained in the straw has been noted, although it is veryslight, of the order of 7%.

[0005] One solution to the above problem that has been proposed is toreplace the three-part stopper with a metal or rigid plastics materialball. This solution has not proved satisfactory because, althoughabsorption of the liquid contained in the straw has been eliminated, newand unacceptable difficulties have arisen, the stopper no longerproviding a liquid seal.

[0006] The patent FR-A-2 753 367 proposes a straw including a three-partstopper comprising a hydrogel powder between two plugs, namely anexternal plug and an internal plug, said straw being characterized inthat the length of the external plug is at least twice the length of theinternal plug. According to the above patent, absorption of the liquidcontained in the straw is only very slightly reduced compared to thatobserved in a straw fitted with a standard three-part stopper.

[0007] An object of the present invention is to provide a straw fittedwith a stopper that absorbs only a small quantity of a liquid containedin the straw. To be more precise, an object of the invention is toprovide a straw fitted with a stopper that absorbs a quantity of aliquid contained therein at most equal to approximately 4%.

[0008] Other objects and advantages of the invention will becomeapparent on reading the following description.

[0009] The present invention conforms to the above object and provides astraw for the conservation of small quantities of substances, inparticular biological substances, said straw comprising a segment oftube provided, inside one end, with a stopper including gel powder,characterized in that said straw stopper includes a thermoplasticsmaterial core sheathed with filaments constituting a sheath.

[0010] The filaments are preferably synthetic filaments, for examplepolyester filaments.

[0011] The gel powder is a material adapted to be converted on contactwith a liquid into an impermeable gel or paste adhering to the wall ofthe tube to create a sealed stopper.

[0012] The gel powder can be an alginate or polyvinyl alcohol, forexample.

[0013] The sheath can take the form of a braid.

[0014] The braid in accordance with the present invention can bemanufactured by braiding, knitting, weaving or wrapping filaments, forexample synthetic filaments, on an extruded thermoplastics materialcore.

[0015] The filaments of the sheath can be treated to render themhydrophilic or hydrophobic. They are white or colored; in the lattercase, the filaments of the sheath constitute a color-coded indicator ofthe contents of the straw.

[0016] The core can also be colored, also constituting in this case acolor-coded indicator of the contents of the straw.

[0017] Similarly, the gel powder can also be colored, also constitutingin this case a color-coded indicator of the contents of the straw.

[0018] The filaments can be fixed to the core by tension or by means ofan adhesive. A thin thermoplastics material sheath can cover everything.

[0019] In accordance with the invention, the straw can be fitted with athree-part stopper or a one-piece stopper.

[0020] In a first embodiment of the invention, the stopper of the strawaccording to the invention is a three-part stopper.

[0021] It comprises three parts of substantially the same length ordifferent lengths.

[0022] The external part, which is not in direct contact with the liquidcontained in the straw, comprises a thermoplastics material coresheathed by filaments, for example synthetic filaments.

[0023] The internal part, which is in contact with the liquid containedin the straw, is a thermoplastics material core sheathed with filaments,for example synthetic filaments.

[0024] The intermediate part comprises gel powder.

[0025] In a second embodiment of the invention, the stopper of the strawaccording to the invention is a three-part stopper.

[0026] It comprises three parts of substantially the same length ordifferent lengths.

[0027] The external part, which is not in direct contact with the liquidcontained in the straw, is a plug, for example a braid, of a standardfibrous substance, for example viscose polyester.

[0028] The internal part, which is in contact with the liquid containedin the straw, comprises a thermoplastics material core sheathed withfilaments, for example synthetic filaments.

[0029] The intermediate part comprises gel powder.

[0030] In a third embodiment, the stopper of the straw according to theinvention is a three-part stopper.

[0031] It comprises three parts of substantially the same length ordifferent lengths.

[0032] The external part, which is not in direct contact with the liquidcontained in the straw, is a plug, for example a braid, of a standardfibrous substance, for example viscose polyester.

[0033] The internal part, which is in contact with the liquid containedin the straw, comprises a thermoplastics material core sheathed withfilaments, for example synthetic filaments, said core incorporating abore.

[0034] The intermediate part comprises gel powder.

[0035] In a fourth embodiment, the stopper of the straw according to theinvention is a three-part stopper.

[0036] It comprises three parts of substantially the same length ordifferent lengths.

[0037] The external part, which is not in direct contact with the liquidcontained in the straw, is a plug, for example a braid, of a standardfibrous substance, for example viscose polyester.

[0038] The internal part, which is in contact with the liquid containedin the straw, comprises a thermoplastics material core sheathed withfilaments, for example synthetic filaments, said core including acentral braid of hydrophilic or hydrophobic filaments.

[0039] The intermediate part comprises gel powder.

[0040] In the case of a three-part stopper, the total length of thestopper is from approximately 7 mm to approximately 14 mm.

[0041] The external part has a length from approximately 3 mm toapproximately 6 mm.

[0042] The internal part has a length from approximately 2 mm toapproximately 5 mm.

[0043] The intermediate part has a length from approximately 1.5 mm toapproximately 3 mm.

[0044] In a fifth embodiment, the stopper of the straw according to theinvention is a one-piece stopper and comprises a thermoplastics materialcore sheathed with filaments, for example synthetic filaments. Thefilaments of the sheath are impregnated with gel powder.

[0045] In a sixth embodiment, the stopper of the straw according to theinvention is a one-piece stopper and comprises a thermoplastics materialcore sheathed with filaments, for example synthetic filaments, andincludes a central braid of hydrophilic or hydrophobic filamentsimpregnated with gel powder.

[0046] The length of the one-piece stopper according to the invention isfrom approximately 5 mm to approximately 14 mm.

[0047] The straw of the invention suffers very little absorption of theliquid contained therein, of the order of 4% and even less.

[0048] The invention will be described in more detail but in anonlimiting manner with reference to the accompanying drawings, inwhich:

[0049]FIG. 1 is a partial view of a first embodiment of a straw of theinvention,

[0050]FIG. 2 is a partial view of a second embodiment of a straw of theinvention,

[0051]FIG. 3 is a partial view of a third embodiment of a straw of theinvention,

[0052]FIG. 4 is a partial view of a fourth embodiment of a straw of theinvention,

[0053]FIG. 5 is a partial view of a fifth embodiment of a straw of theinvention,

[0054]FIG. 6 is a partial view of a sixth embodiment of a straw of theinvention.

[0055] Referring to FIG. 1, the straw 1 comprises a segment of tube 2provided at one end with a three-part stopper 3.

[0056] The external part 31, which is not in contact with the liquidcontained in the straw, comprises a thermoplastics material core 43sheathed with filaments in the form of a sheath 53.

[0057] The internal part 33, which is in contact with the liquidcontained in the straw, comprises a thermoplastics material core 43sheathed with filaments in the form of a sheath 53.

[0058] The intermediate part 32 comprises gel powder 7.

[0059] Referring to FIG. 2, the straw 1 comprises a segment of tube 2provided at one end with a three-part stopper 3.

[0060] The external part 31, which is not in contact with the liquidcontained in the straw, is a braid made from a fibrous substance.

[0061] The internal part 33, which is in contact with the liquidcontained in the straw, comprises a thermoplastics material core 43sheathed with filaments in the form of a sheath 53.

[0062] The intermediate part 32 comprises gel powder 7.

[0063] Referring to FIG. 3, the straw 1 comprises a segment of tube 2provided at one end with a three-part stopper 3.

[0064] The external part 31, which is not in contact with the liquidcontained in the straw, is a braid made from a fibrous substance.

[0065] The internal part 33, which is in contact with the liquidcontained in the straw, comprises a thermoplastics material core 43sheathed with filaments in the form of a sheath 53. The core 43 includesa bore 8.

[0066] The intermediate part 32 comprises gel powder 7.

[0067] Referring to FIG. 4, the straw 1 comprises a segment of tube 2provided at one end with a three-part stopper 3.

[0068] The external part 31, which is not in contact with the liquidcontained in the straw, is a braid made from a fibrous substance.

[0069] The internal part 33, which is in contact with the liquidcontained in the straw, comprises a thermoplastics material core 43sheathed with filaments in the form of a sheath 53. The core 43 includesa central braid 63.

[0070] The intermediate part 32 comprises gel powder 7.

[0071] Referring to FIG. 5, the straw 1 comprises a segment of tube 2fitted at one end with a one-piece stopper 3.

[0072] The stopper 3 comprises a thermoplastics material core 4 sheathedwith filaments constituting a sheath 5. The filaments of the sheath 5are impregnated with a gel powder 7.

[0073] Referring to FIG. 6, the straw 1 comprises a segment of tube 2fitted at one end with a one-piece stopper 3.

[0074] The stopper 3 comprises a thermoplastics material core 4 sheathedwith filaments constituting a sheath 5 and comprising a central braid 6of synthetic filaments impregnated with gel powder 7.

[0075] The filaments constituting the sheath 5 are impregnated with gelpowder.

[0076] The person skilled in the art will understand that although theinvention is described and illustrated with respect to particularembodiments, many variants thereof can be envisaged that remain withinthe scope of the invention as defined by the accompanying claims.

There is claimed:
 1. A straw for the conservation of small quantities ofsubstances, in particular biological substances, said straw comprising asegment of tube provided, inside one end, with a stopper including gelpowder, wherein said straw stopper includes a thermoplastics materialcore sheathed with filaments constituting a sheath.
 2. The straw claimedin claim 1, wherein said filaments of said sheath are syntheticfilaments.
 3. The straw claimed in claim 2, wherein said syntheticfilaments are polyester filaments.
 4. The straw claimed in claim 1,wherein said sheath takes the form of a braid.
 5. The straw claimed inclaim 1, wherein said stopper is a three-part stopper comprising anexternal part which is not in direct contact with said liquid containedin said straw and an internal part which is in contact with said liquidcontained in said straw, said external and internal parts having betweenthem an intermediate part consisting of gel powder.
 6. The straw claimedin claim 1, wherein said stopper is a one-piece stopper.
 7. The strawclaimed in claim 5, wherein said three-part stopper comprises anexternal part comprising a thermoplastics material core sheathed byfilaments constituting a sheath, an internal part comprising athermoplastics material core sheathed with filaments constituting asheath, and an intermediate part consisting of gel powder.
 8. The strawclaimed in claim 5, wherein said three-part stopper comprises anexternal part comprising a fibrous substance plug, an internal partcomprising a thermoplastics material core sheathed with filamentsconstituting a sheath, and an intermediate part consisting of gelpowder.
 9. The straw claimed in claim 5, wherein said three-part stoppercomprises an external part comprising a fibrous substance plug, aninternal part comprising a thermoplastics material core sheathed withfilaments constituting a sheath, said core including a bore, and anintermediate part consisting of gel powder.
 10. The straw claimed inclaim 5, wherein said three-part stopper comprises an external partcomprising a fibrous substance plug, an internal part comprising athermoplastics material core sheathed with filaments constituting asheath, said core including a central braid, and an intermediate partconsisting of gel powder.
 11. The straw claimed in claim 6, wherein saidone-piece stopper comprises a thermoplastics material core sheathed withfilaments constituting a sheath impregnated with a gel powder.
 12. Thestraw claimed in claim 6, wherein said one-piece stopper comprises athermoplastics material core sheathed with filaments constituting asheath and including a central braid impregnated with gel powder. 13.The straw claimed in claim 1, wherein said filaments of said sheath arewhite.
 14. The straw claimed in claim 1, wherein said filaments of saidsheath are colored, constituting a color-coded indicator of the contentsof said straw.
 15. The straw claimed in claim 1, wherein said core iscolored, constituting a color-coded indicator of the contents of saidstraw.
 16. The straw claimed in claim 1, wherein said gel powder iscolored, constituting a color-coded indicator of the contents of saidstraw.
 17. The straw claimed in claim 1, wherein said gel powder isselected from alginates and polyvinyl alcohol.